Hey Akmal Farid, thanks for the question that you post on my comments. This post is supposed to answer your question. Well as we all know, sound card also known as an audio card is a computer expansion card that facilitates the input and output of audio signals from a computer under control of computer programs. Typical uses of sound cards include providing the audio component for multimedia applications such as music composition, editing video or audio, presentation/education, and entertainment (games). Many computers have sound capabilities built in, while others require additional expansion cards to provide for audio capability.
A codec is a device or program capable of encoding and/or decoding a digital data stream or signal. The word codec may be a combination of any of the following: 'compressor-decompressor', 'coder-decoder', or 'compression/decompression algorithm.
Keep in mind that while most of our codecs are mono, computers by nature handle stereo audio. So either connect only to one input and output or convert the codec mono signal to stereo using a special cable. It's often more straightforward to run recording and playing software when both computer audio channels are used.